CSLA 4 release candidate 0 is now available for download from http://www.lhotka.net/cslanet/download.aspx
We are rapidly closing in on the final release of CSLA 4 with support for .NET 4, Silverlight 4 and Visual Studio 2010. This is primarily a bug fix release, and should be very stable.
There are a couple new enhancements to the ASP.NET MVC support, and a handful of bug fixes focused primarily on XAML data binding and the new business rules system.
Assuming no major issues are discovered in this release candidate in the next week or so, I expect CSLA 4 to release around July 19.